Buy a few extra

If you plan to bring your own glassware (vases, dishes, etc.) make sure to buy a few extra in case a few break en route. When you have extras be sure to add a note to the container you bring them in so whoever sets the items out knows they have not miscounted. The same "extra" principle goes for flower girl baskets, favors, gifts, etc. The day of our wedding we added an impromptu "bell boy" (little boy ringing a bell) as well as a flower girl. Having the extra supplies spared tears and allowed us to seamless integrate the tots into the event.